PC Hands down, but obviously u only listed consoles in the poll, ill suggest changing the title thread to "What Console do you think is the best" or include the PC in there as well, since this is under the Gaming Discussion thread, PC Games also fall under this, but meh... im just nit picking xD
The PS3 is best in my opinion. The online features are way better and you don't have to pay. All you are paying for on XBL is a 99.9% no lag system. PS3 has much better graphics support and PS3 is ahead in HD Movies.
In terms of consoles, the PS3, hardware-wise will last you much longer because the technology is quite a bit newer than that used in the Xbox 360. I feel that because of the limit of DVD media, on the Xbox 360 you can either go for quality or amount of game data, but with the PS3's BluRay disc, a combination of both is achievable.
Otherwise, generally, PC is the best "console" out there because of the amount of games available for the platform and the amount of customizability with it, such as choice of mouse, keyboard and game controllers.